A weighing machine inside a stationary lift reads 50 kgf, when a man stands on it. What would happen to the weighing machine reading, if the lift is moving with constant velocity and constant acceleration?

Asked by Topperlearning User | 5th Jun, 2014, 05:00: PM

Expert Answer:

Apparent weight, W' = m(g + a), where a is the acceleration with which the lift moves upwards.

(1) When the lift moves with constant velocity, a = 0

Therefore, W' = m(g + 0) = mg = 50 kgf (weight remains the same)

 

(2) When the lift moves with the acceleration a in the upward direction, we have

W' = m (g + a)  50 kgf

Hence, the apparent weight will increase if the lift will move with acceleration a.

Answered by  | 5th Jun, 2014, 07:00: PM